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path: root/drivers/power/apm_power.c
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2015-03-14power_supply: Change ownership from driver to coreKrzysztof Kozlowski1-1/+1
Change the ownership of power_supply structure from each driver implementing the class to the power supply core. The patch changes power_supply_register() function thus all drivers implementing power supply class are adjusted. Each driver provides the implementation of power supply. However it should not be the owner of power supply class instance because it is exposed by core to other subsystems with power_supply_get_by_name(). These other subsystems have no knowledge when the driver will unregister the power supply. This leads to several issues when driver is unbound - mostly because user of power supply accesses freed memory. Instead let the core own the instance of struct 'power_supply'. Other users of this power supply will still access valid memory because it will be freed when device reference count reaches 0. Currently this means "it will leak" but power_supply_put() call in next patches will solve it. This solves invalid memory references in following race condition scenario: Thread 1: charger manager Thread 2: power supply driver, used by charger manager THREAD 1 (charger manager) THREAD 2 (power supply driver) ========================== ============================== psy = power_supply_get_by_name() Driver unbind, .remove power_supply_unregister() Device fully removed psy->get_property() The 'get_property' call is executed in invalid context because the driver was unbound and struct 'power_supply' memory was freed. This could be observed easily with charger manager driver (here compiled with max17040 fuel gauge): $ cat /sys/devices/virtual/power_supply/cm-battery/capacity & $ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind [ 55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 55.732584] pgd = d98d4000 [ 55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000 [ 55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM [ 55.746210] Modules linked in: [ 55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G W 3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496 [ 55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000 [ 55.771647] PC is at 0x0 [ 55.774182] LR is at charger_get_property+0x2f4/0x36c [ 55.779201] pc : [<00000000>] lr : [<c034b0b4>] psr: 60000013 [ 55.779201] sp : daf55e90 ip : 00000003 fp : 00000000 [ 55.790657] r10: 00000000 r9 : c06e2878 r8 : d9b26c68 [ 55.795865] r7 : dad81610 r6 : daec7410 r5 : daf55ebc r4 : 00000000 [ 55.802367] r3 : 00000000 r2 : daf55ebc r1 : 0000002a r0 : d9b26c68 [ 55.808879] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 55.815994] Control: 10c5387d Table: 598d406a DAC: 00000015 [ 55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210) [ 55.827451] Stack: (0xdaf55e90 to 0xdaf56000) [ 55.831795] 5e80: 60000013 c01459c4 0000002a c06f8ef8 [ 55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4 [ 55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80 [ 55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001 [ 55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000 [ 55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000 [ 55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124 [ 55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550 [ 55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364 [ 55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c [ 55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000 [ 55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000 [ 55.929744] [<c034b0b4>] (charger_get_property) from [<c0346864>] (power_supply_show_property+0x48/0x20c) [ 55.939286] [<c0346864>] (power_supply_show_property) from [<c027f25c>] (dev_attr_show+0x1c/0x48) [ 55.948130] [<c027f25c>] (dev_attr_show) from [<c0146218>] (sysfs_kf_seq_show+0x84/0x104) [ 55.956298] [<c0146218>] (sysfs_kf_seq_show) from [<c0144c78>] (kernfs_seq_show+0x24/0x28) [ 55.964536] [<c0144c78>] (kernfs_seq_show) from [<c0107f90>] (seq_read+0x1b0/0x484) [ 55.972172] [<c0107f90>] (seq_read) from [<c00e53dc>] (__vfs_read+0x18/0x4c) [ 55.979188] [<c00e53dc>] (__vfs_read) from [<c00e548c>] (vfs_read+0x7c/0x100) [ 55.986304] [<c00e548c>] (vfs_read) from [<c00e5550>] (SyS_read+0x40/0x8c) [ 55.993164] [<c00e5550>] (SyS_read) from [<c000f1a0>] (ret_fast_syscall+0x0/0x48) [ 56.000626] Code: bad PC value [ 56.011652] ---[ end trace 7b64343fbdae8ef1 ]--- Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> [for the nvec part] Reviewed-by: Marc Dietrich <marvin24@gmx.de> [for compal-laptop.c] Acked-by: Darren Hart <dvhart@linux.intel.com> [for the mfd part] Acked-by: Lee Jones <lee.jones@linaro.org> [for the hid part] Acked-by: Jiri Kosina <jkosina@suse.cz> [for the acpi part] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-03-14power_supply: apm_power: Use power_supply_*() API for accessing function attrsKrzysztof Kozlowski1-2/+2
Replace direct calls to power supply function attributes with wrappers. Wrappers provide safe access in case of unregistering the power supply (e.g. by removing the driver). Replace: - get_property -> power_supply_get_property Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Jonghwa Lee <jonghwa3.lee@samsung.com> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Reviewed-by: Sebastian Reichel <sre@kernel.org> Signed-off-by: Sebastian Reichel <sre@kernel.org>
2012-03-11device.h: cleanup users outside of linux/include (C files)Paul Gortmaker1-0/+1
For files that are actively using linux/device.h, make sure that they call it out. This will allow us to clean up some of the implicit uses of linux/device.h within include/* without introducing build regressions. Yes, this was created by "cheating" -- i.e. the headers were cleaned up, and then the fallout was found and fixed, and then the two commits were reordered. This ensures we don't introduce build regressions into the git history. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-07-08apm_power: Fix style error in macrosKen O'Brien1-4/+4
Two macros in the changed file contained complex expressions which were not enclosed by parentheses. Signed-off-by: Ken O'Brien <kernel@kenobrien.org> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
2010-09-08apm_power: Add missing break statementAnton Vorontsov1-0/+1
The missing break statement causes wrong capacity calculation for batteries that report energy. Reported-by: d binderman <dcb314@hotmail.com> Cc: <stable@kernel.org> Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
2008-07-22Driver Core: add ability for class_for_each_device to start in middle of listGreg Kroah-Hartman1-1/+1
This mirrors the functionality that driver_for_each_device has as well. We add a start variable, and all callers of the function are fixed up at the same time. The block layer will be using this new functionality in a follow-on patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-02apm_power: check I.intval for zero value, we use it as the divisorAnton Vorontsov1-0/+3
Signed-off-by: Anton Vorontsov <cbou@mail.ru>
2008-02-02apm_power: support using VOLTAGE_* properties for apm calculationsDmitry Baryshkov1-21/+70
It's pretty dummy, but useful for batteries for which we can only get voltages. Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com> Signed-off-by: Anton Vorontsov <cbou@mail.ru>
2008-01-25power supply : use class iteration apiDave Young1-48/+68
Convert to use the class iteration api. Signed-off-by: Dave Young <hidave.darkstar@gmail.com> Cc: Anton Vorontsov <cbou@mail.ru> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-05apm_power: calculate to_full/to_empty time using energyAnton Vorontsov1-25/+53
This patch adds ability to calculate time using energy. Needed to calculate time_to_full for PMU batteries. Signed-off-by: Anton Vorontsov <cbou@mail.ru>
2007-10-05apm_power: improve battery finding algorithmAnton Vorontsov1-10/+47
Prior to this patch, if use_for_apm unspecified, apm_power able to choice batteries according to their charge only. This patch adds ability to choice batteries according to their charge, energy, use_for_apm flag, and fallback to any battery if it failed to decide. Patch is mandatory to report Apple PMU batteries through legacy /proc/apm interface using power supply class. Signed-off-by: Anton Vorontsov <cbou@mail.ru>
2007-10-05apm_power: fix obviously wrong logic for time reportingAnton Vorontsov1-12/+10
Prior to this patch, apm_power was unable to report "to empty"/"to full" time for batteries that hardware-report these values, such as Apple PMU batteries. Signed-off-by: Anton Vorontsov <cbou@mail.ru>
2007-07-15Power supply class and drivers: remove non obligatory return statementsAnton Vorontsov1-4/+0
Per Jeff Garzik request. Signed-off-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: Anton Vorontsov <cbou@mail.ru>
2007-07-10[BATTERY] APM emulation driver for class batteriesAnton Vorontsov1-0/+243
Signed-off-by: Eugeny Boger <eugenyboger@dgap.mipt.ru> Signed-off-by: Anton Vorontsov <cbou@mail.ru> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
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